A New Magnetically Buck-Boost Inverter Based on Switched-Inductors Cell for Output Voltage Regulating in Fuel Cell Applications

This study presents a reliable and improved impedance source inverter with high voltage gain for dc-ac power conversion needed in traction drives of fuel cell vehicles (FCVs). Due to wide voltage range of the fuel cell (FC), the traditional inverter and motor must be oversized to prepare the great constant power speed ratio. Unlike traditional PWM inverter, the presented topology without a battery has self-boost capability because of the unique impedance network when the traction motor is operating at low speed and low power. In this paper, a novel asymmetrical Γ- source inverter with a switched inductor cell that obtains a high voltage gain by a small duty ratio is introduced. In proposed inverter, input current is continuous and the switched inductor cell could prevent the inrush current at the start up. In addition, bucking and boosting capability of this novel inverter is higher than SL Z-sources were presented in previous literatures. Increasing the voltage of the motor to the desired level without need to add new components (inductors and diodes in switched inductor cell) is a major advantage of the novel inverter compared with prior SL Z-sources. In this topology, a coupled inductor withΓ Γ shape is used and voltage gain is increased significantly by lowering transformer turns ratio which could reduce the cost, weight, size and improves the efficiency. The performance of the inverter is verified with simulation results in MATLAB/SIMULINK. As well as, the inverter is analyzed in steady state and the simple boost control is used for simulations.

Keywords:

fuel cell vehicles , traditional PWM inverter , Z-source inverter , switched inductor cell , simple boost control